1. Field of the Invention
This invention relates to and has amont its objects to a novel immune serum globulin and novel methods for its production. Particularly, the invention is concerned with an immune serum globulin having a high titer of naturally occurring antibody to cytomegalovirus (CMV). Further objects of the invention will be evident from the following description wherein parts and percentages are by weight unless otherwise specified.
2. Description of the Prior Art
Hyperimmune serum globulins, i.e., immune serum globulins having high titers of a particular antibody, are thereapeutically useful in treating patients deficient or in need of that particular antibody. For example, tetanus hyperimmune globulin is useful in treating tetanus, and rabies hyperimmune globulin, rabies. It is well known that hyperimmune serum globulins can be produced from plasma or serum obtained from selected donors who have significantly higher titers for a specific antibody than is normally found in the average population. These donors have either been recently immunized with a particular vaccine (U.S. Pat. No. 4,174,388) or else they have recently recovered from an infection or disease [Stiehm, Pediatrics, Vol. 63, No. 1, 301-319 (1979)].
Although clinical disease from cytomegalovirus (CMV) is not common among the general population, it is encountered very frequently in certain susceptible groups of patients. Immumosuppressed organ transplant and cancer patients have been identified as having an unusually high risk of acquiring severe, and sometimes fatal, CMV infection.
Zaia et al in The Journal of Infectious Diseases, Vol. 137, No. 5, 601-604 (1978) disclosed a practical method for preparation of Varicella-Zoster (VZ) Immune Globulin. Outdated blood was screened for complement-fixing antibody to VZ virus. About 15% of the plasma units has a complement-fixation titer equal to or greater than 1:16, with about 7.5% greater than or equal to 1:32.